Originally published in LabTalk (Volume 3, Issue 4, 2008), the quarterly newsletter of Aculabs.
September was “National Prostate Cancer Awareness Month.” The goal of this annual event is to generate widespread awareness regarding prostate cancer and to give the public an opportunity to learn more about it and how to reduce their risk.
Prostate cancer remains an important public health problem in the United States because it is the most common tumor in men and the second leading cause of cancer death in men, with an estimated 186,320 new cases and 28,660 deaths in 2008 according to statistical data from the American Cancer Society (ACS). More than 70% of cases are diagnosed in men over age 65 years. Age, ethnicity and family history are associated with increased risk of prostate cancer; and recent studies suggest obesity and a diet high in saturated fat be considered increased risk factors.
In the early stage, prostate cancer has no symptoms. Even as the cancer progresses, the symptoms are not specific to the prostate. The gold standard for diagnosing prostate cancer is the prostate biopsy. The PSA (Prostate Specific Antigen) blood test and digital rectal exam (DRE) are the primary tools used to help determine the need for a prostate biopsy. Total PSA has served as an excellent indicator of prostate disease, when the concentration is above 4 ng/mL. When PSA is <2 ng/mL the probability of prostate cancer in an asymptomatic person is small; however, when PSA is >10 ng/mL the probability of cancer is high, and a prostate biopsy is recommended. For results in the grey zone (4 – 10 ng/mL), the ratio of free/total PSA has been widely used in clinical practice to differentiate between benign and malignant prostate diseases, and has been reported to reduce unnecessary biopsies.
Screening for prostate cancer is one of the most controversial issues in the medical field today. The American Urological Association and the ACS recommends the Prostate Specific Antigen (PSA) and the digital rectal exam be offered annually to men who have a life expectancy of at least 10 years. For men at high risk (African American, family history) testing should begin at the age of 45. ACS also recommends that information be provided to the patient about the benefit and limitations of early prediction and treatment of prostate cancer.
Recently, in an article published in the August 5 edition of Annals of Internal Medicine, the U.S. Preventive Services Task Force (USPTF) recommended screening stop at age 75, citing statistics suggesting many men are overdiagnosed, based on screening. In addition, for men over 75 years old, with a life expectancy less than 10 years, the potential harm associated with screening (the discomfort of biopsy, possible false positive results and resulting psychological distress) and even the complications that often result from treating prostate cancer can outweigh the benefits of detecting prostate cancer early.
On the other hand, several studies have been published that suggest the decline in the prostate cancer rate and death rate is due to PSA screening, and if the PSA is detecting cancers that are harmless, the death rate should not decline; so the battle continues, with to screen or not to screen remains the big question.
– Dr. Rita Khoury
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